Ultrasonic surgical procedures

ABSTRACT

THE METHOD AND APPARATUS OF THE INVENTION USE ULTRASONIC ENERGY IN THE FORM OF MECHANICAL VIBRATORS TRANSMITTED BY A TOOL MEMBER TO CLOSE OF SMALL SEVERED BLOOD VESSELS, SUCH AS IN HUMANS, BY THE FORMATION OF CLOSURES AT THE TERMINAL PORTIONS THEREOF, AND STOP WHAT IS CALLED &#34;OOZES,&#34; THAT REQUIRED CONSTANT MOPPING OR CLEANING TECHNIQUES DURING AN OPERATION THIS TOOL MEMBER MAY BE IN THE FORM OF A KNIFE ULTRASONICAL VIBRATED TO SIMULATEOUSLY SEVER AND CLOSE OFF RESPECTIVE TERMINAL PORTIONS OF THE SEVERED BLOOD VESSEL WHILE PERFORMING SURGICAL PROCEDURES. THE TOOL MEMBER, OF A PROPER CONFIGURATION, MAY ALSO JOIN TOGETHER LAYERS OF TISSUE, INCLUDING THE WALL OF UNSEVERED BLOOD VESSELS, AND WITH RESPECT TO THE LATTER IS FORESEEN AS REPLACING THE &#34;TYING OFF&#34; OF ARTERIES AND VEINS CURRENTLY NECESSARY IN SURGERY.   D R A W I N G

United States Patent 1191 Balamuth 1451 Feb. 26, 1974 [73] Assignee:Ultrasonic Systems, lnc.,

Farmingdale, N.Y.

22 Filed: Sept. 10, 1971 211 Appl.No.: 179,459

Related US. Application Data [62] Division of Ser. No. 678,649, Oct. 27,1967, Pat. No.

Banko 128/24 A 3,636,943 l/l972 Balamuth 128/24 A PrimaryExaminer-Channing L. Pace [5 7] ABSTRACT The method and apparatus of theinvention use ultrasonic energy in the form of mechanical vibrationstransmitted by a tool member to close of small severed blood vessels,such as in humans, by the formation of closures at the terminal portionsthereof, and stop what is called oozes, that requires constant moppingor cleaning techniques during an operation. This tool member may be inthe form of a, knife ultrasonically vibrated to simulateously sever andclose off respective terminal portions of the severed blood vesselswhile performing surgical procedures. The tool member, of a properconfiguration, may also join together layers of tissue, including thewalls of unsevered blood vessels, and with respect to the latter isforeseen as replacing the tying off of arteries and veins currentlynecessary in surgery.

21 Claims, 29 Drawing Figures PATENIEnftazs I974 EAK TOOL VELOCITYFREQUENCY OF VIBRATION sum 1 0r 5 PRESSURE APPLIED WITH TOOL MECHANICALVIBRATION ENERGY ABSORPTION IN TISSUE TOOL WORKING SURFACE CUTTING EDGETOO-L TEMPERATURE OXYGEN FOR CLOTTING FRICTIONAL RUBBING HEATDEVELOPMENT IN TISSUE TISSUE CLOSURE OR JOINING INVENTOR. LEWIS BA LAMUTH ATTORNE PATENTEDFEBZBIW 3.794040 sum 2 m5 GENERATOR MEANS INVENTOR.LEWIS BALAMUTH ATTORN PATENTEUFEBZBIQM 3.794.040

' sum 3 or 5 F/G.3B F/6.3A

INVENTOR. LEWIS BALAMUTH PATENTED 3. 794. 040

SHET 5 BF 5 58h F/G l0 /2A INVENTOR. LEWIS BALAMUTH ULTRASONIC SURGICALPROCEDURES CROSS-REFERENCE TO RELATED APPLICATION This is a division ofU.S. Pat. application Ser. No.

678,649, filed Oct 27, 1967 now U.S. Pat. No. 5

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relatesgenerally to improvements in surgical procedures whereby ultrasonicenergy is utilized and more particularly to methods and apparatus forclosing off the terminal portions of severed blood vessels to stop orprevent the flow of blood therefrom during the surgical procedure andthe joining of layers of tissue in biological organisms such as humans.

The outstanding and unexpected results obtained by the practice of themethod and appartus of the present invention, are attained by a seriesof features, steps and elements, working together in inter-relatedcombination, and may be applied to biological organisms in general andparticularly humans, and hence will be so illustrated and described withrespect to humans.

Applicant has already participated in earlier developments which led toU. S. Pat No. 3,086,288 covering the use of an ultrasonically vibratingscalpel or knife. The aim of that invention was to increase the easewith which a surgical knife could be used to cut organic tissues.

We are concerned in the present invention with new discoveries byapplicant which allow dramatic improvements in the operation of highfrequency vibrated knives, and also extend the use of the side area orworklaries comprise an area which is as much as 100,000 times the areaof the arteries and veins, and thus it is seen that many morecapillaries are involved per incision than any other vessels. Thesevering of capillaries produces an ooze of blood which must be moppedup or swabbed during an operation, while the larger blood vesselsinvolved must be clamped or tied off to prevent bleeding during thesurgery. The attending of these bleeding problems takes up about 67percent of the time of most operations. It is a major aim of thisinvention to reduce this lost time considerably and at the same time toreduce the total loss of blood and to promote the healing of the woundscreated. This is accomplished by the design of ultrasonic instruments soas to enhance those uses of ultrasonic energy needed to accelerate thedesired objective, namely to stop bleeding.

Ordinarily, bleeding stops by virtue of the interaction between smallbodies in the blood stream called platelets and the oxygen in the air,whereby the platelets disintegrate and form a network of fibers calledfibrin which slow up and finally stop the blood flow by the formation ofsuitable clots. Heat may be used to accelerate this process, and in factboth electric cautery and hot wire cautery are used in controllingbleeding in some procedures. But these types of cautery produce, inaddition to rapid clotting, an extensive destruction to all tissue,thereby requiring a long time in the healing. By means of ultrasonicenergy it is possible to promote the clotting with far less damage, aswill be disclosed 0 herein, so that bleeding may be very quickly haltedand ing surface of a knife to perform a useful function, es-

warm blooded animals and humans) is comprised of two great and complexsystems of arteries and veins. The arteries carry blood from the heartand these arteries divide in a complex network of smaller arteries orarterials, which in their turn connect to an extraordinarily complexnetwork of very fine blood carrying tubes called capillaries. Thesecapillaries are in communication with all the cells of the body and theyprovide the nutrients needed to feed these cells and they also supplythe white blood cells needed to dispose of wastes and, in general, topolice the cells and their environment in respect to unwanted substancesand agents. After doing their job, the blood cells find their way backto the heart by means of a similar network of capillaries which join upto veinules or small veins, which in turn connect to veins whichultimately bring the blood back to the heart. There is also a lymphsystem which participates in this process, wherein again small tubescontaining lymph (a kind of blood plasma with white corpuscles and wasteproducts) convey this lymph through various strainers called lymph nodesand then, ultimately by means of the thoracic duct the purified lymphflow back into a large vein in the neck.

Now when the body is cut into at any location, in general a number ofthe tubes or vessels carrying blood are severed in this region. Thisseverance will include many capillaries, some small veins and arteriesand in some cases even a regular artery or a vein or both. The capilatthe same time, much quicker healing will take place.

Electric and hot-wire cautery as well as cryogenic techniques are noteffective for the care of bleeding from veins and arteries and it ishere that special tyingoff methods or hemistatic clamping techniques areused. It is a further aim of this invention to teach how tying-off andclamping techniques may be replaced by utilizing ultrasonic energy inthe proper way.

In all the ways whereby ultrasonic energy is used in this invention, thetool member supplying the energy executes vibrations of high frequencyand small amplitude. Since the development of the ultrasonic knife, inpart by present applicant, new alloys have become generally availablewhich permit the maximum amplitude of vibration at a given frequency tobe increased substantially. For example, in regular use a scalpel couldbe vibrated at 20 Kc/sec with a stroke of two to at most fourthousandths of an inch. A larger stroke would cause a rapid fatiguefailure of the ultrasonic motor driving the scalpel. With a new alloy oftitanium (titanium with 6 Al 4V is one such) it is possible to go tostrokes as high as 8 or 10 thousandths of an inch. This means that therubbing action of a single stroke may be greatly enhanced, because thepeak velocity achieved during the stroke is more than double the peakvelocities previously attainable on a practical basis.

This improvement led applicant into the development of procedures andtools whereby such large ultrasonic motions could be put to work to stopcapillary bleeding while cutting the surrounding tissue. In order tounderstand this, let us consider the transfer of energy which occursduring cutting. Wherever the tissue comes into contact with the cuttingtool or scalpel, the tool member is moving to and fro at high frequencyparallel to the surface of the tissue being severed. To the extent thatthere is good acoustic coupling between tissue and tool, there will be atransfer of shear waves into the tissue. But, tissue is of an acousticnature as to be practically incapable of supporting high frequency shearwaves. Therefore, the shear waves damp out very rapidly and dissipatetheir energy in the superficial tissue as heat. This promotes fibrinformation and clotting at the capillaries, while the damage tounderlying tissue is minimal due to lack of penetration of this clottingenergy. To the extent that the tool slips past the tissue during its toand fro motion, a rubbing action is set up, due to relative motion oftool and tissue and a frictional heat is generated at the tool tissueinterface, again producing a heating and clotting action on the adjacentterminal portion of the opened capillaries and other blood vessels.Thus, entirely due to the ultrasonic to and fro motion of the tool, acoopeative dual effect is engendered whereby the ooze during anoperation is effectively stopped while cutting.

Applicant has further found that the peak rubbing speed, which equals 1rfx the peak to and fro stroke (f frequency of tool) is relativelyconstant with respect to frequency. This is because the peak strain setup in the ultrasonic motor driving the cutting tool depends directly onthe peak speed of the cutting tool and not on the peak frequency. Ofcourse, this merely means that if one wishes to operate at a higherfrequency, then one has to be content with a proportionately dimin-.

ished to and fro stroke of the tool. In any case, due to the cooperativeeffect, above outlined, essentially all of the energy of the tool isused in local, superficial heating, except for that used to actuallysever the tissue itself. This latter component of energy is only a smallfraction of the total energy used.

In actual practice, applicant has discovered that, by texturing orroughening the side walls of the cutting tool, the transfer ofsuperficial cauterizing energy is increased so as such for certainsurgical procedures it is preferable to use scalpels whose workingsurfaces or side faces are roughened rather than very smooth. The sameprinciple applies to spatulate tools wherein no cutting is contemplated,but the tool is designed primarily to cauterize an already opened bed ofblood vessels such as capillaries in a wound. In the case of thespatulate tool the amount of energy transfer may be increased bypressing the spatula tool working surface, while vibrating, withincreased pressure against the wound to apply a compressive force forthe transmission of the shear waves or increasing the frictionalrubbing. Applicant has also discovered, that although it is notessential, it is nevertheless desirable to supply the cutting edge of aknife or scalpel with a set of small serrations. This further aids inclotting, and permits faster cutting, while at the same time haltingcapillary bleedmg.

Now, in addition to all of the above there are still additional aidsarising from the use of ultrasonic energy during the cutting operation.This arises because the collagenous substances in the walls of thecapillaries and also in those of veins are arteries, are capable ofbeing joined or sealed together by the application of said highfrequency energy. In fact, it is just this property which makes itpossible to close off a vein or an artery by clamping it in a speciallydesigned ultrasonic instrument, so that the walls of said blood vesselare briefly clamped while vibrating one or both of the tool jaws. Sincethis same principle applies to other soft body tissue such as the skin,this same type of tool may be used in place of the conventional suturingwhich is used in closing incisions in surgical procedures.

Thus, it may be seen that we are dealing with a highly complicated setof phenomena in practicing applicant's method of bloodless surgery. Atthis time, it is not known quantitatively just how large a role isplayed by each factor, such as shear wave absorption, frictional heatproduction and tissue sealing'The point is that by employing ultrasonicmotors capable of producing generally higher strokes than previouslyavailable, the combination of effects permits for the first time, truebloodless surgical procedure by ultrasonic means. Where extremely fastprocedures are essential, one may also resort to auxiliary heating ofthe vibrating tool member, but only to sub-cautery temperatures. Thistemperature is preferably above room temperature but below a temperaturethat would normally burn the tissue. This may be accomplishedconventionally, or in accordance with the method disclosed in U. S. Pat.No. 3, 321,558 in which applicant is a co-inventor.

OBJECTIVES OF THE INVENTION An object of the present invention is toprovide an improved method and apparatus for performing surgicalprocedures with ultrasonic energy.

Another object of the present invention is to provide an improved methodand apparatus for securingv together layers of tissue in biologicalorganisms, such as humans.

Yet another object of the present invention is to provide an improvedmethod and apparatus for forming closures at the severed terminalportions of blood vessels in vivo, which blood vessels are in thegeneral neighborhood of what are called capillaries, so as to preventooze, which requires contact mopping or cleansing during surgicaloperations.

A further object of the present invention is to provide improved methodand apparatus for permanently or temporarily closing off blood vesselsso as to replace the tying off of arteries and veins currently necessaryin surgery.

Still another object of the present invention is to provide a method andapparatus of bloodless surgery which combines the surgical cutting oftissue and a closing off of the severed blood vessels to prevent theooze associated with operations.

Yet still another object of the present invention is to provide a methodand apparatus for simultaneously joining and trimming, as by cutting, alarge blood vessel.

Yet still a further object of the present invention is to provide animproved method and apparatus for ultrasonically joining together layersof tissue.

Still a further object of the present invention is to provide animproved method and apparatus for increasing the flow of oxygen to theterminal portion of the severed blood vessel to expedite the clotting ofthe blood thereat.

Still yet a further object of the present invention is to provide animproved sealing apparatus for joining together layers of human tissue.

Still yet a further object of the present invention is to providespecially designed tools adapted to be ultrasonically vibrated andemployed in surgical procedures.

Other objects and advantages of this invention will become apparent asthe disclosure proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS Although the characteristic featuresof this invention will be particularly pointed out in the claims, theinvention itself, and the manner in which it may be made and used, maybe better understood by referring to the following description taken inconnection with the accompanying drawings forming a part hereof,-whereinlike reference numerals refer to like parts throughout the several viewsand in which: g

FIG. I is a chart indicating the relationship of the principal factorsaffecting the practicing of the present invention for surgicalprocedures;

FIG. 2 is an assembled somewhat schematic view of an ultrasonic motorgenerator system of the type in which the motor is capable of being handheld and manipulated, for driving a tool member adapted to engage thebiological organism for performing a surgical procedure, and which inthe present instance the tool member is illustrated as a knife forsevering blood vessels, the latter shown on a greatly enlarged scale fordiscussion purposes;

FIG. 3 is a side view of an ultrasonic tool member having a texturedworking surface in accordance with the present invention;

FIGS. 3A and 3B are end views of the tool member in FIG. 3 andillustrates two preferred ways of obtaining the textured workingsurface;

FIG. 4 is a greatly enlarged schematic representation of a portion of atool member with its working surface in engagement with the terminalportion of a blood vessel for forming a closure thereat to prevent theflow of blood from said terminal portion;

FIG. 4A is an enlarged section view taken along line 4A4A of FIG. 4 toillustrate the interfacial contact between the tool'working surfaceandblood vessel for the transmission of frictional energy and shearwaves for localized heating of the terminal portion;

FIG. 4B is a greatly enlarged schematic representation illustrating anultrasonically vibrating tool member engaging a severed portion oftissue for simultaneously forming a plurality of closures at theterminal portions thereof;

FIG. 4C'is a greatly enlarged schematic representation illustrating theangular relationship between the tool member and blood vessel whichdefines a terminal plane that may define an extreme angle with the axisof the blood vessel and still obtain the desired results of the presentinvention;

FIG. 4D is an end view of the tool member and blood vessel of FIG. 4C;

FIGS. 5, 5A, 5B and 5C are enlarged schematic representations incross-section of the method of forming a closure at the terminal portionof a blood vessel in which the side walls thereof are joined together;

FIG. 5D is an extremely enlarged view of a blood specimen to illustratesome of the important components thereof;

FIGS. 6 and 6A are enlarged schematic representations in cross-sectionof the method of forming a closure at the terminal portion of a bloodvessel in which the closure is formed by partially converging the sidewalls thereof and forming a blood clot in the reduced opening;

FIGS. 7 and 7A are enlarged schematic representations in cross-sectionof the method of forming a closure at the terminal portion of a bloodvessel in which the closure is formed by primarily forming a blood clotat the terminal portion thereof;

FIGS. 8 and 8A are side and end elevational views respectively, of aspatula tool member having a textured working surface for ultrasoniccautery;

FIG. 9 is an enlarged sectional view illustrating the forming of aplurality of closures on respective terminal portions in an open woundby the use of a spatula shaped tool;

FIG. 10 is a top longitudinal view, of one preferred form of ultrasonicsystem, of the type capable of being hand held and manipulated, forjoining together layers of tissue, such as in humans;

FIG. Ill is a side longitudinal view, partly in crosssection, of theultrasonic system of FIG. 10;

FIG. 12 is an enlarged schematic view, in crosssection, illustrating theapplication of the ultrasonic instrument illustrated in FIGS. 10 and 11for securing together the walls of a blood vessel;

FIG. 12A is an enlarged schematic view, in crosssection, similar to FIG.12 illustrating the actual joining of the overlapping wall portions;

FIG. 12B is a further enlarged schematic view, in cross-section, showingthe actual bond obtained between the wall portions of the blood vessel;

FIG. 12C illustrates the ultrasonic system as used for simultaneouslyjoining and cutting layers of tissue; and

FIG. 112D illustrates the ultrasonic system clamping means forintermittently joining overlapped layers of tissue.

DETAILED DISCUSSION OF THE DRAWINGS The high frequency transducer meansmay be either in the sonic or ultrasonic frequency range but forpurposes of the present invention the word ultrasonic will be used todenote vibrations in the range of approximately 5,000 to 1,000,000cycles per second. In addition the term blood vessel as used herein isintended to include any tubular member of the human body, butparticularly capillaries, arterials, veinules, arteries and veins.

In performing the surgical procedures of the present invention there areseveral factors that have to be taken into consideration and analyzed interms of a total or effective value to obtain the desired end results.The term total value" may be defined as the proper combination of thesefactors to obtain the desired end result.

Referring now to the drawings, FIG. I is a chart illustrating therelationship of the seven principal factors which are involved in thewhole or in part for determining the total value associated with formingclosures at the terminal portions of severed blood vessels, or joiningtogether overlapping segments of layers of human tissue. The relatedfactors are peak tool velocity, frequency of vibration, pressure appliedwith tool, tool working surface, cutting edge, tool temperature andoxygen for clotting. These factors vary with respect to the procedurebeing performed.

In the embodiments of the invention discussed below the working surfaceof the tool member is placed in engagement with at least one of thelayers of tissue at a surface thereof such that a small compressiveforce is applied in a plane substantially normal to the engaged surface.While this compressive force is maintained the working surface of thetool member is vibrated at an ultrasonic rate to apply an additionalenergy producing force at the engaged surface. The compressive andenergy producing forces are continued until the layers of tissue aresecured together by the combined action of these forces.

When these layers of tissue form the walls of a blood vessel the forcesare applied to the terminal surface thereof for producing localizedheating in forming a closure to prevent the blood from escapingtherefrom. The energy producing force may be divided into mechanicalvibration energy absorption in tissue and frictional rubbing heatdevelopment in tissue both of which result in a localized heating of thewalls of the blood vessel to obtain the tissue closure. The performingof surgical procedures as related to this aspect of the invention isdiscussed with reference to FIGS. 2 through 9, inclusive.

In contrast to this we have the joining of layers of tissue inoverlapping relation to each other and in which case the compressive andvibrational forces are applied to one of the overlapped surfaces in aplane substantially normal thereto and in which case we primarily relyon mechanical vibration energy absorption in tissue to obtain the tissuejoining. The performing of surgical procedures as related to this aspectof the invention is discussed with reference to FIGS. 10 through 12D,inclusive.

Referring again to the drawings, and with respect to FIG. 2, it will beseen that an apparatus 10 for ultrasonically performing surgicalprocedures on a biological organism, such as a human, may include anultrasonic transducer or motor 11 for effecting the necessary highfrequency vibrations of the tool member 13, such as a knife, having asharp output edge or surface 15 with a working surface 16. Theultrasonic motor 11, as illustrated may be in the form of a drivingmember adapted for being hand held as by an operator 12, and generallycomprising a tubular housing or casing 14 into which an insert unit 17supporting the tool member 13 may be partially telescoped. Theultrasonic motor 11 is energized by an oscillation generator 18, with apower cable 19, connecting the two together. The generator is anoscillator adapted to produce electrical energy having an ultrasonicfrequency.

The ultrasonic motor 11 may be one of a variety of electromechanicaltypes, such as electrodynamic, piesoelectric and magnetostrictive. Theultrasonic motor for effecting surgical procedures through hand directedtools of suitable configuration, which are readily replaceable orinter-changeable with other work performing tools in acousticallyvibrated material treating devices, may be of the type disclosed in U.S. Pat. Nos. Re 25,033, 3,075,288, 3,076,904 and 3,213,537, and whereineach work too] member is rigidly joined, in end-to-end relationship to aconnecting body or acoustic impedance transformer and to a transducerwhich may form an insert unit or assembly which is removably supportedin a housing containing a coil in surrounding relationship to thetransducer and receiving alternating current for producing analternating electromagnetic field.

The transducer in the ultrasonic motor 11 is longitudinally dimensionedso as to have lengths which are whole multiples of half-wavelengths ofthe compressional waves established therein at the frequency of thebiased alternating current supplied so that longitudinal loops of motionas indicated by arrow 23, occur both at the end of the insert unit 17 towhich the tool member 13 is rigidly connected and the knife edge. Thus,

the optimum amplitude of longitudinal vibration and hyper-accelerationsof tool member 13 is achieved, and such amplitude is determined by therelationship of the masses of the tool member 13 and insert unit 17which may be made effective to either magnify or reduce the amplitude ofthe vibrations received from the transducer.

The tool member 13 may be in the form of relatively flat metal spatulamember, as shown in FIGS. 8 and 8A, hereinafter discussed in detail, toprovide relatively wide surface areas for contact with the tissue towhich the vibrations are to be applied for effecting the closure ofsevered blood vessels.

The tool member 13 may be permanently attached to the end of insert unit17, for example, by brazing, solder or the like, or the tool may beprovided with a threaded stud 20 adapted to be screwed into a tappedhole in the end of insert unit 17 for effecting the rigid connection ofthe tool to the stem. A base portion 21 is provided from which the stud20 extends, from one end thereof, and from the other end a body 28 whichis firmly secured thereto for the transmission of the ultrasonicvibrations. The body 28 may be brazed or welded to the base 21 of thetool member 13. A tapered surface 22 may be provided which connects thecutting edge 15 with the working surface 16.

As seen somewhat schematically in FIG. 2 the biological organism 25,such as a human, contains a layer of outer tissue or skin 26, aninternal cellular structure 27 with a plurality of blood vessels 30extending therethrough shown in an enlarged scale, as well as in theskin (not shown).

FIGS. 3, 3A and 3B illustrate various types of replaceable surgicalimplements, such as knives, that may be employed in accordance with thepresent invention. The knife 13a of FIG. 3 is similar to thatillustrated in FIG. 2 and includes a base portion 21a, capable ofsupporting ultrasonic vibrations and adapted to be set into vibration ina given direction by the driving member. A threaded stud 20a extendsfrom one end of the base 21a for engagement with the insert unit. Thebody portion 28a, in the form of a cutting blade, extends from theopposite end of the base 21a and includes a textured working surface 16afor enhancing the coupling action between the tool member 13a and theterminal portion of the severed blood vessels to be engaged. The cuttingedge 15a may be serrated and have an outwardly tapered portion 22abetween the cutting edge 15a and the substantially flat working surface16a. The textured surface 16a may begin in close proximity to or startat the working edge 15a so that when cutting and sealing'smallcapillaries the rubbing action and transmission of shear waves beginsimmediately. The textured surface finish of 16a may vary from a microfinish in the range of 10 micro-inch to 10,000 micro-inch, butpreferably in the range of 40 micro-inch to 200 microinch.

As illustrated in FIG. 3A the tool member 13a includes a body portion28a having a coated textured layer of friction inducing material 29awhich forms the working surface 16a and which may be of diamond or steelpowder particles bonded to the body portion in any conventional mannerwell known in the art, to obtain the desired micro finish. The layer ofcoated material may be applied to both surfaces of the tool member andeach surface may be of the same or different micro finish to obtain adebriding and superficial cauterizing.

The advantages are quicker healing as well as less damage to the tissuebeing treated.

FIG. 3B illustrates the obtainment of the working surface 16abyfinishing the metallic body 28a in any conventional manner to obtainthe desired surface roughness. By providing the textured surface it ispossible to control the rate of frictional heating of the blood vessels.The surface roughness is generally selected in accordance with theultrasonic rate of vibration and the compressive force to be applied.This will in many instances relate to the particular surgeon performingthe operation.

THEORY OF PRESENT INVENTION Whereasa scientific explanation of thetheory based on the phenomena involved is disclosed below, it is to beclearly understood that the invention is by no means limited by any suchscientific explanation.

Applicant has now discovered that mechanical vibrations properly appliedmay produce closures at the terminal ends of blood vessels to preventthe flow of blood therefrom and also join together layers of humantissue. With respect to forming the terminal closure it is possible tosimultaneously cut through layers of tissue and seal off the terminalends.

For purposes of illustration, we have in FIGS. 4 and 4A a single bloodvessel 3012 having a wall 311; with a terminal portion 33b terminatingin an end surface 3212, the latter in engagement with the workingsurface 16b of the tool member 13b which is being ultrasonicallyvibrated in the direction 23b.

At the interface of the working surface 16b and terminal surface 32b wehave a transmission of both rubbing forces and mechanical vibrationalenergy to the blood vessel 30b which results in a localized heating ofthe terminal portion 33b. FIG. 4A illustrates the contour of thesurfaces in engagement with each other and the transmission of the shearwaves over the distance D. The pressure applied with the tool member,partially determines the degree of shear waves and rubbing vibrationstransmitted to the terminal portion 33b of the blood vessel for a giventextured tool. At point P shear vibration is developed in the tissue31a, then at P the shear vibration has dropped almost to zero wherebythe shear vibration energy is converted into heat in the tissue of theblood vessel. The smallness or minimal depth of penetration of P P iswhat makes for quick healing and cauterizing action of the tool member.

The shear wave pattern 35b extends the distance D, which is the distancefrom If to P along the blood vessel 30b to obtain the localized heatingof the terminal portion. The coupling action at the working' surface161) and'blood vessel 30b is enhanced by the application of the smallcompressive force, as indicated by arrow 36b, in a plane substantiallynormal to the plane defined by said terminal end surface 32b. At P inaddition, to the extent that shear vibration is not induced in thetissue, there will be a slippage and a frictional rubbing action whichwill also produce heat practically instantaneously at P It is acombination of these effects which create the closure at the terminalportion of the blood vessel.

It will be appreciated that the relative amounts of shear vibration andfrictional rubbing action will be determined or selected by themagnitude of the tool vibration and the tool surface in relation to thetissue surface. Many combinations are possible whereby either thefrictional or the shear components may be emphasized.

' The extent that the rise in temperature occurs at the terminal portion33b of the blood vessel 30b is related to the rubbing vibrations appliedand this is related to the peak speed which is:

Vpeak=2rrfA A peak amplitude f frequency V peak velocity So that if f israised, A is lowered and we can retain the same peak speed at allfrequencies. This is why the more rubs per second the higher thefrequency for the same output peak speed. Accordingly the workingsurface ll6b of the tool member 13b may be surface finished forsufficient roughness to allow increased friction against the tissue.This is quite different from a standard knife or scalpel which haspolished sides.

The thickness of the tool member should also be held to a minimum so asto permit a .more rapid local temperature rise which is attributable tothe shear production and absorption in the adjacent tissue and thetemperature rise due to rubbing of tissue surface, which involvesslippage between tool member and tissue surfaces. We can say that duringthe to and fro motion, neglecting the energy of cutting itself, when aknife is used we have:

Ultrasonic energy per stroke Ultrasonic shear energy produced per strokeFrictional rubbing energy per stroke.

Since, in both cases the energy absorbed goes into superficial heatingof tissue and cutting tool, we can estimate the effects by consideringall the energy to be fric' tional for ease of making approximatecalculations.

Assuming an average force of friction, P, we have the power dissipatedsuperficially at a tool tissue interface equal to:

S Stroke F average friction force P power Now V max. for a frequency of20 lKc/sec and a stroke of 0.010 inch is approximately 50 FPS. ThereforeP is approximately 15 watts, when F is between one half and one pound.Since this power is dissipated in a superficial region of the cutting,the heat capacity of the tissue and the tool are quite small. Forexample for a steel tool of dimension 1 inch X 0.125 inch X 0.010 inchthe total heat capacity is only a few hundreths of a gram. In such acase it is possible to obtain local temperature rises of the order ofhundreds of degrees centigrade under the condition outlined above. Thisis ample to stop ooze.

Accordingly the frequency and amplitude of vibration of said tool memberis selected at a level wherein the transmitted shear waves aresubstantially maintained at the terminal portion 33b with onlysuperficial penetration and heating of the remainder of the blood vessel30b.

Accordingly, the frequency and amplitude of vibration is preferablyselected at a level to provide a peak velocity of at least 10 feet persecond along the working surface 16b of the tool member 13b and moregenerally the general range of approximately 40 feet per second to feetper second.

FIG. 4B shows a portion of the biological organism 25b with an outerlayer of skin 26b and a plurality of blood vessels 30b extending throughthe cellular structure 27b and terminating against the working surface16b of the tool member 13b. The tool member 13b is being vibrated at anultrasonic rate in the direction of arrow 23b, which is in a planesubstantially parallel to the plane defined by the terminal end portions33b, to induce shear waves 35b, which penetrate the blood vessels 30band surrounding tissue structure 27b. The high frequency vibration andamplitude of the tool member is selectedto obtain only a superficialpenetration and resulting heating of the terminal portion 33b so thatthere is a minimum of damage to the underlying tissue area 31b and allof the blood vessels are simultaneously closed off. I

As illustrated in FIGS. 4C and 4D the terminal portion 33b has an endsurface 32b that defines a plane 37b that may vary in angularrelationship to the axis of the blood vessel 30b. In practice theangular engagement between the working surface 16b of the tool member13b and the end surface 32b may not always be controlled during asurgical procedure since the blood vessels such as capillaries,veinules, veins, arterials and arteries extend in various directionsthroughout the body. The important consideration is that the ultrasoniclongitudinal mechanical vibrations, as indicated by arrow 23b, areapplied having a major component of vibration parallel to the terminalplane 37b and a component of compressive force, as indicated by arrow36b, in a plane substantially perpendicular to the terminal plane 37b.

FIGS. 5, A, 5B, 5C, 6, 6A, 7 and 7A illustrate the actual surgicalprocedure in vivo of obtaining a closure at the terminal portion of ablood vessel using the ultrasonic instrument illustrated in FIG. 2, or atool member illustrated in FIGS. 4, 4A and 4B. As explained with respectto the theory of the present invention in FIGS. 3, 3A, 3B, 3C and 3D thedegree of shear waves and frictional rubbing may be controlled so that apredominant reliance on one or the other is produced.

In FIGS. 5, 5A, 5B and 5C the terminal closure 40c is formed primarilyby producing a plastic flow of the wall of the blood vessel andcontinuing the flow for a period of time sufficient to obtain a joiningof the severed ends together. Initially the cutting edge c of the toolmember 13c is placed in engagement with the skin 260 of the body 250 andthe tool member 130 is ultrasonically vibrated and a small compressiveforce in the direction of arrow 360 is applied to obtain a cutting ofthe skin 26c and progressively sever the tissue by a continued movementof the cutting edge 15c through the cellular material 270 until the wall310 of the blood vessel 300 is engaged. The wall 310 for purposes ofdiscussion is considered as layers of tissue 42c and 430, respectively.

As seen in FIG. 5A after the cutting edge 15c severs the tissue layer42c a certain amount of blood 44c flows from within the blood vessel 30cinto the opening 450 that has been formed. As the movement of theultrasonic instrument is continued downwardly we have the engagement ofthe working surface 16c with the terminal end portion 330 of the bloodvessel to apply a compressive force to the end surface to obtain alocalized heating of the terminal portion by the application of theultrasonic mechanical vibration.

The relative movement is continued so that the application of themechanical vibrations are transmitted for a period of time sufficientfor the localized heating to form the closure 400 at the terminalportion 33c. In this manner the terminal portion 33c is closed off bythe formation of the closure 45c and the blood contained therein isprevented from escaping through the closure. The closure 45c is producedat least in part by the production of said shear waves and theirconversion into heat coupled with the localized heating obtained byinducing frictional rubbing at the terminal portion 330. The extent ofeach factor will vary with the texture of the working surface and thedegree of the compressive force applied by the working surface againstthe terminal portion.

FIG. 5D is an enlaged microscopic examination of the blood 44c and asillustrated the blood contains red corpuscles 46c, white corpuscles 47cand platelets 48c, the latter play an important role in the naturalclotting of blood by producing fibrin when exposed to air. This naturalclotting ability of blood is relied upon at least in part with respectto the formation of the closures illustrated in FIGS. 6, 6A, 7 and 7A.

FIGS. 6 and 6A illustrate the formation of the closure which issubstantially formed by clotting of the blood at the terminal position.The working surface 16d is placed in engagement with the layers of wall42d and 43d of the blood vessel 3011, which is of a size in thecapillary range, with the blood 44d contained therein. The tool member13d preferably has a textured surface to permit air and most importantlyoxygen to be delivered past the layer of skin 26d to the terminalportion 33d of the blood vessel to obtain a clotting action. The toolmember 16d acts as an ultrasonic pump and stimulates the flow of air tothe work site. As the air reaches the work site we have the additionalaction of the conversion of the ultrasonic mechanical vibrations toobtain a localized heating by the conversion of the frictional motioninto heat and the localized heating expediates the formation of theblood clot 50d which forms the closure 40d. Since the blood vessel isrelatively small in diameter we have the formation of the closure 40dthat is substantially formed by a clotting of the blood 44d therein. Asseen in FIG. 6A the tool member is then removed leaving the opening ofwound 45d and closures 40d formed on each respective end of the severedblood vessels.

FIGS. 7 and 7A illustrate the formation of a closure 40:: by partiallyclosing the layers 42c and 43e of the wall 31c of the blood vessel 30::at the terminal portions 33c by the localized heating and the remainderby forming a blood clot 502 of the blood 44c contained in the reducedarea of the blood vessel. The ultrasonic tool member 136 transmits themechanical vibration which produces a plastic flow of the wall 3le ofsaid blood vessel which flow is continued for a period of time to obtaina reduced cross sectional area and during which same period of time thelocalized heating assists in the formation of the blood clot 50e whichtogether with the reduced area forms the closure 40:: to prevent theblood from escaping therefrom. The tool member is then removed past theskin 262 leaving the opening 45c.

It is appreciated that the process although illustrated for a singleblood vessel can be occurring simultaneously on a plurality of bloodvessels. To increase the rate at which the closure is formed and reducehealing time the working surface of the tool member may be heated to atemperature level which is above room temperature, but below atemperature that would normally sear the terminal portion of the bloodvessel. The temperature of the tool may be heated in any conventionalmanner, as for example, in accordance with US. Pat. No. 3,321,558.

There are instances in surgical procedures where it is desirable to beable to stop bleeding independently of having previously cut the tissueof the body. As for example, in gunshot wounds and other accidents it isoften desirable to stop bleeding and accordingly spatula like tools inaccordance with the present invention may be utilized.

FIGS. 8 and 8A illustrate one form of readily replaceable implement, inthe form of a spatula like tool member 13f, having a body portion 28fwith substantially flat parallel working surfaces 16f, that have beentextured to a preselected micro finish to provide means for coupling theultrasonic vibration to the terminal portions of the blood vessels. Thesurface finish is selected for the transmission of rubbing vibrationsand shear waves to obtain the localized heating. One end of the spatulabody portion 28f is fixedly secured to the base portion 21f, and thelatter has a threaded stud 20f for securement to the ultrasonic drivingmember. The base portion 21f is preferably of a metallic materialcapable of supporting ultrasonic vibrations and adapted to be set intovibration in a given direction at ultrasonic frequencies. The bodyportion 28f may be in the order of 0.010 to 0.160 inches thick and beconcave in configuration for strength reasons. It may also be designedto vibrate elliptically to permit intermittent separation of the toolmember and terminal portions to promote the flow of air to theterminalportions for clotting.

As illustrated in FIG. 9 the spatula like tool member is illustrated forsurgical procedures in which it is desired to form closures at terminalends of blood vessels 30g separately from when the actual cutting isperformed. Accordingly the spatula like tool 13g is inserted within theopening 45g of the body 25g such that the working surface 16g of thetool member 13g applies a compressive force against the terminalportions 33g of the severed blood vessels. The compressive force isapplied in the direction of arrow 36g. The tool Hg is simultaneouslyvibrated, in a direction as indicated by arrow 23g, and' at anultrasonic rate to transmit mechanical vibrations to the terminalportion 33g of the blood vessels to obtain a localized heating of atleast some of the terminal portion. The application of said compressiveforce and mechanical vibrations are continued until a closure at theterminal portion is formed and the blood contained therein is preventedfrom escaping through the form closure. The thickness of the spatulatool member 133 may be narrower, as illustrated in FIG. 9, than theopening 45g in the body, such that only one surface 163 engages thesevered blood vessels. If desired the width of the spatula body 28g maybe substantially equal to that of the body opening 45g so that bothterminal ends 33g of a respective blood vessel 303 is closed during oneinsertion of the tool member within the wound.

The localized heating to obtain the closures may be induced byfrictional rubbing at the terminal portion 33g of the blood vessel 30gso that the closure is produced at least in part by frictional heating.By providing a textured surface to the tool member 13g the rate offrictional heating may be controlled when combined with the otherfactors to produce the terminal closure.

Depending upon the thickness of the spatula tool member either purelongitudinal vibration will be obtained or a flexural component ofmotion, as indicated by the arrow 51g, so as to obtain ellipticalvibrational motion along the working surface 16g. This permitsintermittent disengagement between the wall surface or terminal end ofthe blood vessel 33g and the working surface 16g so that air and in turnoxygen may be continuously supplied to the work site to assist in theclotting of the blood. I

FIGS. 10 and 11 illustrate one form 10h of the ultrasonic system forjoining together in vivo, overlapping layers of organic tissue. Thesystem includes a hand held instrument including an ultrasonic motor11h, which may be the type as discussed with reference to FIG. 2, andinclude a tool member 13h having an enlarged portion 53h terminating ina working surface 16h that extends in a plane substantially normal tothe direction of mechanical vibrations illustrated by the arrow 23h. Thebase 21h of the tool member 13h is secured to the insert portion 17h.Support means 55h is provided to act as an anvil or clamp so that theoverlapped layers of tissue 42h and 43h of the wall 31h of the bloodvessel 30h may be compressed between the vibratory working surface and asupport surface.

The support means 55h includes a pair of legs 56h and 57h respectively,secured together at their lower end by bands 58h and provided withgripping means in the form of individual lugs 59h that extend outwardlyfrom the upper end of the legs for engagement by the fingers of thesurgeon or operator 12h in a manner hereinafter described. The leg 57hhas a lower extension 60/: that terminates in a support arm 61h atsubstantially right angle to the extension 60h, and is provided with asupport surface 62/1 in spaced relation to the working surface 16h ofthe tool member 13/1.

The legs 56h and 57h are in spaced relation to each other and may becontoured to conform to the cylindrical configuration of the ultrasonictransducer housing Mb. The generator 18h is connected to the transducer11h by means of cable 19h in a conventional manner. As seen in FIG. 10the cable 19h may enter the ultrasonic motor llh from the side so as toleave the rear end 63h free for engagement by the thumb or any otherfinger of the surgeon to permit manual control of the relativedisplacement between the overlapping working and support surfaces.

The support means 55h is mounted for relative movement, with respect tothe ultrasonic motor 11h by providing a pair of slots 65h on each of thelegs 56h and 57h, and which slots accept headed fasteners 66h whichextend from the casing 14h through the slots 65h to permit free relativemovement between the ultrasonic motor 11h and support means 55h. Thelower end of the casing 14h is provided with an annular shoul der 67hwhich is adapted to receive spring means in the form of a spring 68hwhich is contained within the shoulder 67h at one end thereof and inengagement with the bands 5% at the opposite end thereof. The spring 63happlies a force in the direction of arrow 68h, so that the workingsurfaces of the support means and ultrasonic motor means are biassedaway from each other whereby the force applied by the surgeon isrequired to bring the overlapping working and support surfaces together.If desired the spring may be coupled to the support and ultrasonic motormeans so as to force them together with a predetermined static forcewhich might be varied in a conventional manner not shown. In this manneronce the static force is determined for the particular thickness oftissue the resultant permanent or temporary seal may be obtained.Accordingly the spring means may yieldably urge the support means 55hand transducer means 11h relative to each other to a position whereinthe working and support surfaces 16h and 62h, respectively, are normallyin engagement with each other under a predetermined static force, sothat the support and transducer means are first separated for theplacement of the layers of tissue 42h and 43h therebetween. In contrastto this the spring means may be adjusted such that the working andsupport surfaces are normally maintained in spacially fixed relation toeach other, so that the layers 42h and 4311 are positioned between thesurfaces which are brought together by the operation of the hand heldinstrument.

As previously explained during surgical procedures it becomes necessaryto tie-off veins and arteries so as to prevent the flow of bloodtherethrough. In accordance with the invention the joining of the wallsmay be of a permanent or semi-permanent nature, and this is accomplishedby properly selecting the frequency and amplitude of ultrasonicmechanical vibrations to produce an optimum flow of the collagenouselements contained in the overlapping portions of tissue. Thiscollagenous material is similar to that normally found in the formationof scar tissue. In practice the ultrasonic instrument h may be employedto join together, at a select area the wall of a blood vessel and asseen in FIG. 10 the wall 31h may be considered to include theoverlapping layers of tissue 42h and 43h.

As seen in FIGS. 12, 12A and 12B we have the blood vessel 30h exposedwithin an opening 45h within the organic body 25h. To produce a joiningof the overlapping layers of wall tissue 4211 and 43h respectively, thearm 61h of the support means 55h is placed beneath the blood vessel 30hand the working surface 16h of the tool member 13h is brought intocontact with the layer of tissue 42h. The working and support surfaces16h and 62h are moved relative toward each other until the blood vessel30h has the overlapping layers of tissue 42h and 43h in contact witheach other as seen in FIG. 12A. Simultaneously therewith a smallcompressive force, in the direction of arrow 36h, is applied to thelayers of tissue traversing the area of overlap.

The working surface of the tool member 13h is vibrated at an ultrasonicrage, as for example, in the frequency range of from Kc/sec to 100Kc/sec and preferably in the range of 20 Kc/sec to 40 Kc/sec, so as toapply an additional recurring force to the overlapped layers of tissue,and produce a superficial heating at the interface of the overlappedlayers. The vibrational force has a substantial component of vibrationnormal to the overlapped surfaces, as indicated by the arrow 23h. Thefrequency of the ultrasonic rate of vibration is selected in the abovefrequency range so as to preferably also produce an optimum flow of thecollagenous elements in the overlapped layers of tissue. The energy isthen continually applied until a closure or bond 40h is formed betweenthe collagenous elements in the overlapping layers of tissue, as seen inFIG. 12B, and the blood is prevented from flowing past the closure. Theclosure 40h may be of a temporary nature or permanent one depending uponthe proper control of the vibratory energy and static force to fusetogether the superficially heated interface.

For certain applications it is desirable to join together theoverlapping layers of tissue and at the same time cut off the excessmaterial. As illustrated in FIG. 12C the support ann 61 j is providedwith a cutting edge j and as the overlapped layers of tissue 42j and 43jare compressed between the working surface 16j and support surface 26jand joined together by the energy transmitted through the tool memberl3j and the excess tissue layers 71j and 72j are cut off. If desired thecutting edge may be placed on the working surface l6j of the tool memberl3j.

For those applications in which it is desired to intermittently jointogether overlapping layers of tissue we have the apparatus illustratedin FIG. 12D. The overlapping layers of tissue 42k and 43k are firstclamped together by clamping means 75k which includes clamping members76k and 77k which may form part of the ultrasonic instrument or may bethe forward portion of a pair specially designed clamping instrument.The clamping means 75k is applied in close proximity to the area ofoverlap of the layers of tissue 42k and 43k to the joined together. Theultrasonic instrument 10k includes the support means 55k for engagingone side of the overlapped layers of tissue and which opposite side isengaged by the tool member 13k which is illustrated is provided with acircular working surface. By intermittently moving the ultrasonicinstrument along the area of overlap a number of closures or bonds 30k,such as stitches may be formed.

While the invention has been described in connection with particularultrasonic motor and tool member constructions, various other devicesand methods of practicing the invention will occur to those skilled inthe art. Therefore, it is not desired that the invention be limited tothe specific details illustrated and described and it is intended by theappended claims to cover all modifications which fall within the spiritand scope of the invention.

I claim:

1. A method of preventing the flow of blood from a severed blood vesselin vivo, with the aid of a tool member having a working surface,comprising the steps of A. applying the working surface of said toolmember against the terminal portion of said blood vessle to apply acompressive force thereto,

B. simultaneously vibrating the working surface of said tool member in adirection and at an ultrasonic rate to transmit mechanical vibrations tothe terminal portion to obtain localized heating of at least some ofsaid terminal portion,

C. continuing the application of said compressive force and mechanicalvibrations until a closure at said terminal portion is formed, wherebythe blood contained therein is prevented from escaping through saidclosure, and

D. providing said working surface of the tool member at a temperaturelevel which is above room temperature, but below a temperature thatwould normally sear the terminal portion of the blood vessel, wherebythe healing time is substantially reduced.

2. A method as claimed in claim 1, wherein said localized heating isobtained by inducing frictional rubbing at the terminal portion of saidblood vessel by the application of said mechanical vibrations, wherebysaid closure is produced at least in part by said frictional heating.

3. A method as claimed in claim 1, further including the step ofcontrolling the rate of frictional heating of the terminal portion ofsaid blood vessel.

4. A method as claimed in claim 3, wherein said rate of frictionalheating is controlled by texturing said tool working surface to asurface roughness selected in accordance with the ultrasonic rate ofvibration and compressive force to be applied. V

5. A method as claimed in claim 1, wherein the application of saidmechanical vibrations produce at least in part shear waves at theterminal portion, and the frequency and amplitude of vibration of saidtool member is selected at a level wherein said transmitted shear wavesare substantially maintained at the terminal portion with onlysuperficial penetration and heating of the remainder of said bloodvessel.

6. A method as claimed in claim 1, wherein said frequency and amplitudeof vibration is selected at a level to provide a peak velocity of atleast feet per second along the working surface of said tool member.

7. A method as claimed in claim 6, wherein said peak velocity is in therange of approximately 40 feet per second to 100 feet per second.

8. A method as claimed in claim 1, wherein said working surface isvibrated in an elliptical pattern.

9. A method as claimed in claim 1, wherein said mechanical vibrationsare produced by vibrating the tool member to obtain longitudinalvibrations along said working surface, which working surface ismaintained along a plane substantially parallel to the plane defined bythe terminal portion of said blood vessel.

10. A method as claimed in claim 1, wherein said compressive force isapplied along a line substantially perpendicular to the plane defined bythe terminal portion of said blood vessel.

11. A method as claimed in claim 1, including the step of applying theworking surface of a tool in the form of a knife wherein the workingsurface is a side wall of the tool member is in the form of a knife andsaid working surface comprising a side wall thereof.

12. A method as claimed in claim 11, wherein said knife is employed tosever the blood vessles and said working surface engages the terminalportions and simultaneously forms said closures.

13. A method as claimed in claim 1, including the step of applying saidtool working surface simultaneously to a plurality of terminal portionsof blood vessels.

14. A method of superfically cauterizing severed blood vessles of awound in vivo, with the aid of a noncutting spatula like tool memberhaving a working surface, comprising the steps of A. applying theworking surface of said tool member against the terminal portion of saidblood vessels, said tool member being at a temperature level which isabove room temperature, but below a temperature that would normally searthe terminal portion of the blood vessel, whereby the healing time issubstantially reduced,

B. retaining said tool member in a position relative to said severedblood vessels,

C. maintaining a compressive force applied along a line substantiallyperpendicular to the plane defined by the terminal portion of said bloodvessels with said non-cutting spatula like tool member,

D. simultaneously vibrating the working surface of said tool member, ata peak velocity of at least 10 feet per second and, while maintainingsaid compressive force, in a direction and at an ultrasonic rate totransmit mechanical vibrations to the terminal portion, said localizedheating is obtained by inducing friction rubbing at the terminal portionof said blood vessels by the application of said mechanical vibrations,and

E. continuing the retaining of said tool member in a position relativeto said severed blood vessels and the application of said compressiveforce and mechanical vibrations until a superfic'al cauterization atsaid terminal portion is formed, whereby the blood contained therein isprevented from escap- 15. A method as claimed in claim 14, wherein theapplication of said mechanical vibrations produces at least in partshear waves at the terminal portion, and the frequency and amplitude ofvibration of said tool member is selected at a level wherein saidtransmitted shear waves are substantially maintained at the terminalportion with only superficial penetration and heating of the remainderof said blood vessel.

16. A method as claimed in claim 14, wherein said peak velocity is inthe range of approximately 40 feet per second to feet per second.

17. A method as claimed in claim 14, wherein said mechanical vibrationsare produced by vibrating the tool member to obtain longitudinalvibrations along said working surface, which working surface ismaintained along a plane substantially parallel to the plane defined bythe terminal portion of said blood vessel.

18. A method as claimed in claim 14, wherein said closure is at least inpart formed by a blood clot, and said localized heating expedites theformation of said blood clot.

19. A method as claimed in claim 14, wherein said closure is formed bypartially closing the blood vessel by said localized heating and theremainder by clotting the blood contained in said reduced area of theblood vessel. I

20. A method as claimed in claim 14, wherein said ultrasonic mechanicalvibrations are applied over an area to simultaneously close off aplurality of blood vessels.

21. A method as claimed in claim 14, wherein said mechanical vibrationproduces a plastic flow of the wall of said blood vessel and said flowis continued for a period of time sufficient to obtain a joining of thewall of said blood vessel to form said closure.

